


Ruri-Chan Is His Bae

by LilFantaPants



Series: The Seven Sinful Brothers - Leviathan [1]
Category: Shall We Date?: Obey Me!
Genre: Cosplay, Demon, Demon Form, Demon Sex, Demon/Human Relationships, Dress Up, F/M, First Time Together, Friends With Benefits, Friends to More Than Friends, Kissing, Makeover, Naked Female Clothed Male, Obsessive Nature, Oral Sex, Orgasm, Rough Sex, Sex, Tails, Teasing, Undressing, Vaginal Fingering, Vaginal Sex, ruri-chan, tail teasing
Language: English
Status: Completed
Published: 2020-08-11
Updated: 2020-08-23
Packaged: 2021-03-06 11:00:27
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 4,596
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25848448
Author URL: https://archiveofourown.org/users/LilFantaPants/pseuds/LilFantaPants
Summary: With the help of Asmodeus, Sophie (OC) prepares a surprise treat for her favourite demon.
Relationships: Leviathan/Main Character (Shall We Date?: Obey Me!)
Series: The Seven Sinful Brothers - Leviathan [1]
Series URL: https://archiveofourown.org/series/1883833
Comments: 8
Kudos: 66





	1. The Element of Surprise

**Author's Note:**

> This is the first part Levi's story in The Seven Sinful Brothers collective
> 
> Sophie (OC for the Levi Story) is female, and is addressed by she/her pronouns.

“Oooh Sophie! You look so cute!” His hands clasped to his face, Asmodeus purred as he admired his handiwork. “Levi's going to absolutely love it! Are you ready to see?” You bet I'm ready. After spending the best part of four hours being a literal dress-up doll for the Avatar of Lust, I'm certainly intrigued at my cosplay makeover.  
“Hell yes. Show me!” My voice tingled with excitement, an excitable grin spread across my face.  
“Okay, cover your eyes!” I raised my hands to cover my eyes as Asmo guided me towards the full-length mirror behind me, and once I was in place, his soft fingers pulled my hands from my face. The reflection in the mirror was jilting to say the least, for I had gone. Ruri-Chan stood in my place, staring back at me. The lustful demon nuzzled his cheek up against my shoulder – Ruri-Chan's shoulder? And he hummed happily, burying his face into the glossy satin ruffles and frills that laced my puffed sleeve. “Do you like it, Sophie?”  
“I-I... I can't believe that's me,” I stared at Ruri-Chan, and she back at me. Get me away from this mirror, it's too fucking weird. Of course I had my own reservations and concerns about this ridiculous disguise. “And you really think Leviathan will like it?”  
“Oh, I'm sure he will!” Asmodeus crooned, stroking the strawberry-blonde wig that hung in knee-length bunches. “I'm sure that he is going to really like it. When my older brother sees this, he'll be wrapped around your cute little pinky in no time at all. You should go to him now, or I'll be tempted to keep you all for myself!” 

I felt mildly ridiculous walking to Levi's room. It's not that the two bedrooms were exactly far apart – in fact, they were directly across the hallway from one another – but I felt anxious that one of the other residents of the House of Lamentation might happen to bump into me. This obscenely pink candy-coated outfit was so far detached than the skinny jeans, t-shirt and cardigan combination that my entire wardrobe consisted of. My heart racing, I banged on his door. Come on Levi. I knocked louder.  
“Levi, can I come in?” I called out desperately, my eyes scanning up and down the hallway. My fists banged harder against the door, and I nearly punched him in the shoulder when the door finally flung open. His face, oh, his face was an absolute picture. His eyes blew out in incredulous awe and his jaw dropped, a rush of rose-tint flooded to his cheeks.  
“S-Sophie?” He stood unmoving in the doorway, and I pushed past him, making my way into the deep blue comfort of his bedroom. I felt his eyes follow me, wild and bewildered, completely surprised at my makeover. I recalled Asmodeus' advice, cosplay is nothing without the character behind it. The act is just as important as the appearance. It's a shame that I couldn't fucking act to save my life, but here goes nothing.  
“Well, what do you think?” My voice dripped with honey, my face contorted into a coy expression. My hands waved down my outfit, and I span in a pirouette before posing coquettishly. Levi brought the back of his hand up to his face, in futile attempt to hide his blushing visage. His eyes could tell a thousand words at this moment, and a thousand ways of telling me that he loved everything before him. Ironically, none of those words could escape his lips. Those lips opened and closed silently as he tried to formulate sentences, or even mere sounds, the only noise audible was the sound of an uncomfortable gulp in his throat. The door latched behind him, the demonic embodiment of envy stood motionless. I closed the gap between us and looked up at him through the long fluttering lashes that now adorned my lids. Leviathan gasped, his elated amber eyes gleamed in the soft ambient lighting. My arms reached up to hug him around his shoulders, and my favourite otaku squealed in happiness. He likes it. Really, he likes it.

“Did... Did you do this for me?” His face blushed a deeper shade of fuchsia, and I began to melt within the confines of this sickeningly sweet attire.  
“Well, you are Ruri-Chan's number one fan – are you not?” I challenged him toyingly, poking my tongue into my cheek. His eyes widened as they scanned over me.  
“Of course I am!” His face was displeased by my needing to ask such a question, we both knew he was. Levi wasn't one to simply like something, no. Once he discovered something that interested him, he obsessed over it, immersed by it, he had to be their biggest fan – there could never be any contest. The Avatar of Envy had to take it all.  
“Then of course I did this for you.” Leviathan's arms snaked around my waist as he lifted me up to be at equal height to him. “I was thinking... You and I don't have any pictures of just us, and as I've gone through such an ordeal to look like this, how about we change that?”  
“Well, I... I don't really like having my picture taken. But, I think I wouldn't mind if it was with you.” The blushing on his sweet face wasn't giving up any time soon, and I felt my face soften as my mind raced with thoughts of how cute he was at this moment. Slowly my feet neared the ground, and I pulled my D.D.D. from my pocket. As I loaded up the camera app on the phone I could hear him adjust his clothes and fix his hair. I couldn't help but smile to myself, he wanted this to be perfect. I passed him the phone, for his long arms would lend themselves for a better selfie shot. His spare arm wrapped around my side, my torso pushed into his, my head tilted coyly, my hands peace-signs, his face unable to hide his own excitement and elation. We both gazed in awe at the photo. We just looked, like we were meant to... Like we would be happy together. I had an idea.

“Um. How about a full length photo?” My sugary voice inched higher in tone. Levi passed the phone back to me and I propped it up on his desk, with a ten-second timer awaiting. “Ready?”  
“Uh, yeah!” The button was pressed and the countdown began. Back at his side, I positioned my hands on his shoulder, one of my legs lifted playfully behind me. Seven. We watched the timer counting down. Six. He shifted his weight towards me slightly. Five. My tongue darted across my lips. Four. I breathed in. Three. My hand moved up to cup his cheek. Two. His head turned to face mine. One. I leaned up and stole a kiss from him – our first kiss, his arms came crashing around me, pulling me closer to him as he kissed me back. Click. My gloved-hands ran through his soft violet-hair, and my tongue danced along his lip. Leviathan lifted me up and my legs wrapped around his waist, his lips trembled as a soft moan escaped him. And I felt myself resting against his growing erection. His hands wandered to appreciate the frills and flounces of Ruri-Chan's signature pink and white skirt. My breath hitched and my head knocked backwards, my demon's lips moving down to lave and lick at my neck and clavicle. 

We came crashing down onto his bed, a tangled mess of limbs and lips. I hadn't even noticed that he had changed into his demonic form until I felt his heavy tail move up over my socks to graze my inner thigh. His name tumbled from my mouth in a gasping mantra, and he suddenly withdrew himself from me, the tail like a whip as it recoiled from beneath Ruri-Chan's skirt. Panting, laid back on his bed, I looked up at him as he moved back, his hand up to his face in embarrassment. “Are you sure?” Leviathan asked, pained, overcome with a sudden wave of self-consciousness. “A-are you sure you want to... with a yucky otaku like me?” Yes, Levi. It's always been you. I tackled him onto his back, pinning his wrists down as I kissed the scales that had bloomed on his neck. He could very easily overpower me, but he allowed me to restrain him, and I felt him nestle back into the mattress. The demon below me could only whimper and whine hungrily as my tongue trailed over his alabaster neck.  
“Yes. If you want to be with me too.” My reply was soft, yet entirely honest as my words tumbled out to spill onto his collarbone. Leviathan quivered as my tongue traced the contours of his scales, his hips bucked automatically as I gyrated against him. The serpentine tail thrashed playfully against the sheets below us. His erection fought against the fabric of his diamond-patterned trousers, begging to be released. I gazed hopefully into his orange eyes as I slowly moved my hands away from his wrists. He was once again without words, instead opting to convey his decision through a shy nod. Inching myself towards him, my lips parting, he would come to meet me halfway. As we kissed tenderly my arousal started to ache in the deepest pit of my stomach, longing for him to pull the tension out of me. Long, trembling fingers travelled over Ruri-Chan's absurdly sweet costume, appreciating every bow, flower and frill that would rise and fall heavily over my panting torso. He reached up to relieve me of the ridiculous cat-eared cap that was seated atop my head, tossing it to the floor. Delicate blue-tipped fingers skimmed down the long, stupid ponytails that fell along my sides, then moved to hold me by the waist. I was running my hands through his violet locks as he laid my down onto my back. 

Levi moved down to position himself at my feet, admiring Ruri-Chan's signature ankle-boots. My left leg was lifted as he slowly pulled his favourite anime character's questionable taste in footwear from me. They landed across the room with a soft thud, and the other also landed only moments after. Leviathan's tail snaked between my legs, constricting itself around my thigh. His hands ran over the over-knee white socks I was wearing for him. I much preferred it when he started to casually slip them off, and when he nibbled at the sock's toe and pulled it back with his teeth I felt my arousal gradually seep into my panties. The very tip of his tail lightly flicked and strummed against the lace that lay over my clit. Our breaths were ragged as he carefully stripped me of all the ludicrous fancy-dress that clung to my trembling body. Piece by piece, Ruri-Chan slipped away from me and onto the floor around us. I was in front of him now, almost naked and unashamed. Because he wasn't about to fuck Ruri-Chan, no. Me. Fuck you, Ruri-Chan.


	2. No Turning Back

**Summary for the Chapter:**

> Sophie (OC) and Levi finally take their friendship and pact to the next level...

Widened amber eyes regarded my heaving body. The growing knot in my stomach twisted deeper as his gaze searched carefully over me, and I felt my cheeks flush hot – it had been a long time since I had felt the eyes of a lover upon me, let alone one who would be a demon. Like me, Levi was quiet, but I could tell that his mind was roaring with a thousand racing thoughts. The soft humming and bubbling of Henry 2.0's filter, the mechanical whirring of his water-cooled PC, the second hand ticking on his limited edition TSL Lord of Shadows clock signed by Christopher Peugeot himself... These ordinarily quiet sounds that once provided a comforting level of white-noise had turned deafening, and the rushing beat of blood pumping through my veins rang like an chorus through my ears. We were both still – me laying back, stripped amongst the pillows and he knelt in his full demonic glory between my feet. His thick tail thumped and flicked at the mattress in a manner that was both playful and eager in equal measure. Both him and I knew what we were supposed to do next. However, neither one of us were taking any leads with this. “Um, maybe you could... touch yourself?” I croaked, suddenly aware of a lump forming thick in my throat. Leviathan's nose wrinkled, his face appeared almost pained. I had already regretted my poor choice in words.  
“Wh-why would you want me to do that?” Blazing orange eyes vanished behind the mop of violet hair as he hung his head bashfully. “I'm not some... lewd exhibitionist of a demon like Asmo...” The corners of his mouth contorted in disgust as he struggled on the word 'lewd' and he almost choked on his younger brother's name. My heart dropped. I lifted myself away from the bed to be closer to him, but his face turned away from me.  
“I know... I'm sorry.” My apology was sincere, but the abashed demon between my ankles still would not look to me, his hand reached up in effort to conceal his face. “I, I haven't done this sort of thing in quite some time,” The words fell from my lips in a low mumble as my hand stretched out to touch his, my fingers gently weaving between turquoise-tipped extremities. Levi stiffened, but slowly began to turn toward me. His posture relaxed. A pair of golden eyes peered at me through amethyst curtains. In all my life I had never truly imagined that demons could exist, and even if for a moment I could have considered it – they would never have been sheepish. But Leviathan – Avatar of Envy, Grand Admiral of Hell's Navy, Student Council member and frankly one of the most dangerous demons in the Devildom... was truly the exact opposite of how I expected a demon to behave. 

“Neither have I.” He uttered under his breath, his glittering gaze hopefully searching my face for any form of reaction. If he had expected a verbal response from me, he would have been disappointed, for I had no words to offer. Instead, my intertwined fingers drew his hand to rest at my lower back. I leaned forward until my head came to rest on his shoulder. The demon sighed and pulled me closer to him, holding me in a safe embrace whilst the heavy tail constricted around the two of us. His wild and ragged heartbeat thrummed against my chest. I looked up at him hopefully through lidded eyes, and I heard his breath hitch. He trembled ever so slightly as he leaned down to kiss me again, and his hands ran up the small of my back to caress my neck and my hair. “I... I've wanted this for so long.” His words echoed through me, I whimpered quietly as he placed kisses along my jaw to my ear, and when his fangs nibbled slightly at my lobe a light moan escaped me. My hand wandered down his torso to linger over the hardening bulge in his tight trousers. Levi squirmed beneath me as I began to palm at his firmness.  
“May I?”

It was a large and monstrous thing indeed, so perhaps I should have been scared of it - but in truth I didn't fear it at all. I held it in a tight grip and slowly pumped up and down his length, bringing Levi to pant and whine my name hungrily, pleading for more of my touch. The purplish tip throbbed while a pearl of pre-cum dribbled down his shaft, drawing another moan from his lips. He buried his head into my shoulder as I continued to toy with him. Gasping groans muffled into the kisses and nips he planted on my neck and his tail reached around to caress at my hardening nipples. My panties felt cold and damp against my pussy. Oh, Levi. His cock twitched eagerly in my palm.

His eyes were blazing with passion as he laid me down on my back, and that spark in those tangerine eyes thrilled me to my very core, my pent-up tension curling in my stomach. My bum was lifted upwards and my panties were slipped away and discarded to the floor. In a flash his tail whipped around my leg, holding my lower body hoisted skywards, and he had plunged his ravenous tongue between my thighs, thus inciting me to squeal vehemently from sheer surprise. Aqua fingernails dug into my soft thighs as he held my pussy to his mouth. I glanced up to see Levi glaring down at me, clearly unimpressed by my loud outburst. “Shh...” he breathed against my inner thigh, encouraging me to refrain from disturbing the other residents of the House of Lamentation. Neither one of us wished to be interrupted by one of his brothers right now. He would never share, I belonged to him and only him now. Leviathan licked and laved at my hood, enticing my hidden nub to harden under his forked-tongue. Whimpering and gasping, my legs locked around his head, my back arching in ecstasy, knuckles white as they gripped his coralline horns. At first, he growled at the sudden intrusion, but then his grip upon me adjusted, he moved his skilled fingers to tease at my opening, exploring and groping at my growing wetness.  
“Please... Please don't stop!” My whining was desperate, my body trembling, dripping sweat, breaths ragged and my walls pulsing.

Eventually, I was lowered back down on the bed. Neither of us could resist any longer. His plum-hued tip pressed against my entrance eagerly. He studied my visage cautiously as he pushed himself inside, and once he was seated deep within me I began to grind against him, enticing him to buck and tremble, whimpering hungrily. Levi did try to go gentle, I know he did, but he couldn't suppress the overwhelming desires that raged within him, and within moments he was fucking me into oblivion. It was fast, desperate, rough. His face painted a perfect image of lewd, ravenous desire. Turquoise claws gripped at my waist as his head knocked back, mouth agape, whining, crying and drooling as he spilled his load inside me.

The dripping cock retreated from me with a wet plop, and Levi slipped his fingers deep inside me, curling upwards to hit at my g-spot with varying levels of pressure. I cried out for him over and over until his scaled tail snaked into my mouth to quieten me... Fucking hell Levi. I had dreamed of being with you, but never had I thought of this. His mouth descended upon me, sucking at my clit, the pace of his fingers quickened inside my beating pussy. My ecstatic moans were muffled, my back contorted, and my heart threatened to beat out of my chest. I'm sure for a moment my soul left my body as my orgasm ripped through me like a raging tsunami, wave after wave came crashing through me. Tears rolled down my cheeks, my legs kicked and flailed. His tail fell away from my mouth, and he scooped my up in his arms to hold me close to him. “That was... You were...” My brain and my mouth couldn't compute. Leviathan blushed, and leaned down to kiss my lips tenderly, softly. 

Levi woke me when he scooped me up into his arms, carrying me like I were his bride to the bathroom. His cheeks flushed when I spotted the romantic bath that he had prepared. Blue flower petals drifted amongst candles in bubble-shaped cups that floated atop the surface. He carried me in with him, and I lay in his lap whilst he cleaned me gently and tenderly with a sponge, peppering the odd kiss here and there on my nape, ear, shoulder... My eyelids fluttered closed once again while I rested in his arms, contented, blissful. Levi, where have you been my whole life...


	3. Afterglow

**Summary for the Chapter:**

> The final chapter of Ruri-Chan Is His Bae, set the morning after!

**Notes for the Chapter:**

> Note - "Chotto matte" roughly translates to wait a moment, "Matte" meaning wait.

Gentle kisses and nibbles on my shoulder and neck stirred me to wake. My lids slowly fluttered open to find myself held tight in the soft embrace of my Otaku demon lover, his warm lips and sharpened teeth lightly grazing against my collarbone. “Mm, you’re awake,” Leviathan beamed an elated grin as he breathed into my ear, and I giggled lightly in response. He kissed at my love-bitten neck, where he had marked me in a way that matched his own pattern of scales, a warning to all who would lay their envious eyes upon me that I was his lover and that he would not share me. His new obsession. Fuck you, Ruri-Chan.  
“Morning Levi,” I murmured, “Did you sleep well?” His soft cheeks flushed scarlet.  
“I-I did.” The violet-haired otaku stammered, “I… I had you here with me.” Try although he might to hid behind that sweeping amethyst fringe of his, my fingertips pushed his hair from his face to reveal his golden orange eyes. Even after everything, he was still shy around me. I found it so endearingly sweet. "I wish you and I could just stay here forever. Sophie, please don't go back to the Human World." Pain caused his voice to crack and his porcelain face to crease. "If you have to go, take me with you." A deep sigh escaped my lips as my palm reached up to cup his cheek and a salty tear rolled down between my alabaster fingers.

My DDD buzzed on the desk, I had completely forgotten about it, the photo of us that had been the catalyst for last night’s events. It vibrated again, and then a third time. With a disgruntled huff I slipped away from Leviathan and reached for the phone. The House of Lamentation group chat was abuzz, it seemed that Mammon was trying to find me. I began to type a response when someone started frantically banging on Levi’s door.

“Chotto matte!” Levi yelled out in desperation, but it was too late - Mammon swung the door open with Asmodeus peering over his shoulder.  
“S-SOPH?” The scummy second-born cried out, incredulous at my sexed-up state of undress. I had a sheet clutched to my chest, but our intruders could see that I was clearly naked behind it. My tousled hair, smudged makeup and the scent of sex that pooled in the room were certainly hiding no secrets. The sight before them horrified Mammon, yet the Avatar of Lust behind him was completely and utterly captivated. Asmo looked at me with a shit-eating grin plastered on his face and winked. He knew that the Ruri-Chan costume would of course be a hit with his Otaku brother, but I’m not sure he quite expected this. He was impressed.  
“I. SAID. MATTE!” My lover growled out as he shifted into his demonic form, glowering menacingly towards his brothers. Mammon bailed instantaneously, reduced to nothing more than a blinding flash fleeing back into the corridor. The lustful fifth-born only could laugh.  
“I’ll leave you two lovebirds to it then! Enjoy! If you need anything just let me know, candles, massage oils? A condom? A third participant? Just give me a shout!” He called out in a sing-song manner, giggling as he closed the bedroom door. My eyes peered up to Levi, who was stood with his feet parted, head bowed, arms tensed. He was panting as pure rage coursed through his veins. His eyes blazed bright. I could feel the heat of his envious wrath emanating from his infernal form.  
“Levi, they’ve gone now,” I carefully stepped towards him, reaching out to hold his hand. “It’s just us again.” My voice a soft coo in attempt to soothe the destructive aura that radiated from him.  
“They - They…” Leviathan stammered, his face pink. “They saw YOU. Naked!” His focus was unmoving from the door. “I-I’m the only one who can see you like that. It’s not fair.” He whined angrily, tears beginning to well in his eyes. I wrapped my arms around him, my head fell to rest on his shoulder. His stance relaxed slightly under me. “Sophie, you’re MINE.”  
“Yes, I’m yours. Only yours.” My words came out as a warm mumble against his collarbone. His arms wrapped around me in a tight embrace, and his tail snaked around my lower back, constricting around the both of us.

Eventually we went down to the dining room for breakfast, together. I refused to don the ridiculous Ruri-Chan costume again, so I was wearing a pair of Levi’s jogging trousers and one of his t-shirts. His smell was all over me, that gentle scent that somehow smelt of a sea breeze. His six demon brothers’ eyes were fixed upon us as we walked in. Leviathan’s cheeks blazed under the scrutiny of his brothers. Beel came bounding up to me and gave me a big hug. “Soph, I’m really happy for you and Levi, you’re both so good for each other!”  
“W-Well ya know, I was Sophie’s first! Are we all forgettin’ that or what?” The greedy second-born complained. Levi glared at him and soon enough Mammon bowed his blushing face.  
“Shut up Mammon, everyone knows by now that you were Sophie’s ‘first’… I’m just surprised that Levi actually found the ability within him to actually cheat on Ruri-Chan, his ‘one true 2D love’!” Belphegor yawned as he mocked the Otaku.  
“Mm, Sophie! You simply must tell me all about it!” The lewd Avatar of Lust purred, “I have to ask… Has our brother figured out what to do with that thick tail of his? I’m sure that impressive thing could be quite… pleasurable…” He added, winking at me. Satan studied us both, able to decipher the answer to his younger brother’s question merely from the micro-expressions on our faces. The wicked fourth-born demon smirked cruelly, before returning to his book.  
“Asmodeus, that’s enough!” Lucifer commanded, “I won’t tolerate such crude language.” Asmo pulled a sulking face at the eldest, before grabbing me by the arm.  
“Sophie, my dearest… You’ll sit by me this morning!” Levi whined audibly as I was ripped from his side. I shot my introverted demon an apologetic look and gestured at the empty seat at the other side of me. Mammon’s eyes darted up, and before Leviathan could sit next to me, the greedy demon had launched himself into the seat by my side.  
“Mammon!” Levi whined. “It’s not fair! I want to sit by Sophie!”

“Mama, Mama wake up!” Ugh, what time is it? “Mama! Uncle Luci said he is going to take us to the Aquarium! You’ve got to get up Mama!” I can’t help but smile at her, she’s beautiful. Save for the wild red curls of hair that she could only have inherited from me; my baby looks so much like her Dad. Nessie has his slim nose, his smile, the same slender build, and those big, beautiful amber and purple eyes.  
“Morning baby, you just woke me from a dream.” I murmur softly.  
“What was it about Mama?”  
“I dreamed about your Dad.” Nessie’s eyes glow brightly as she jumps up and down on the bed. “It was a memory, a really lovely memory.”  
“Tell me Mama, I want to hear about your stories with Papa!”  
“Ah, baby… This isn’t a story for little ones like you.” My baby’s face drops, and my heart aches to see her sad like this. “But I do have one story about your Dad that you’d love to hear…”


End file.
